Charged pion production in 70 GeV/cK + p interactions

Inclusive charged pion production is studied in an exposure of BEBC, filled with hydrogen, to an incidentK ⁺ beam of 70 GeV/c. Total cross sections for pion production and inclusive longitudinal and transverse momentum distributions of π^?'s and of positive particles are presented and compared with data at lower energies. Earlier evidence for scaling in the fragmentation regions is confirmed. The central region π^? cross section increases proportionally top _LAB ^?1/4 ; positive particles show almost no energy dependence atx=0. Particle ratios π⁺/π^? are studied as a function ofx andy ^* and a comparison with 70 GeV/cK ^? p data is made. Analysis of structure functions for (ππ) pairs and of particle production associated with π^± triggers at large |x| in the context of quark/parton models, provides qualitative evidence for the diquark-quark structure of the proton.     

Gcd of multivariate polynomials via Newton polytopes

We study geometric criteria to determine coprimality between multivariate polynomials. Our main contribution is the development of a polynomial-time algorithm (on the number of monomials) that detects coprimality of multivariate polynomials using Newton polytopes. We also show how to construct the gcd of two bivariate polynomials using their Newton polygons.     

Extracting biological information with computational analysis of Fourier-transform infrared (FTIR) biospectroscopy datasets: current practices to future perspectives

Applying Fourier-transform infrared (FTIR) spectroscopy (or related technologies such as Raman spectroscopy) to biological questions (defined as biospectroscopy) is relatively novel. Potential fields of application include cytological, histological and microbial studies. This potentially provides a rapid and non-destructive approach to clinical diagnosis. Its increase in application is primarily a consequence of developing instrumentation along with computational techniques. In the coming decades, biospectroscopy is likely to become a common tool in the screening or diagnostic laboratory, or even in the general practitioner's clinic. Despite many advances in the biological application of FTIR spectroscopy, there remain challenges in sample preparation, instrumentation and data handling. We focus on the latter, where we identify in the reviewed literature, the existence of four main study goals: Pattern Finding; Biomarker Identification; Imaging; and, Diagnosis. These can be grouped into two frameworks: Exploratory; and, Diagnostic. Existing techniques in Quality Control, Pre-processing, Feature Extraction, Clustering, and Classification are critically reviewed. An aspect that is often visited is that of method choice. Based on the state-of-art, we claim that in the near future research should be focused on the challenges of dataset standardization; building information systems; development and validation of data analysis tools; and, technology transfer. A diagnostic case study using a real-world dataset is presented as an illustration. Many of the methods presented in this review are Machine Learning and Statistical techniques that are extendable to other forms of computer-based biomedical analysis, including mass spectrometry and magnetic resonance.     

Proficiency testing in food microbiology: experience from implementation of ISO/IEC 17043 and ISO/TS 22117

The proficiency testing (PT) scheme ??AQUA?? for food microbiology was organised by the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) according to ISO/IEC 17043 and ISO/TS 22117. This paper describes the IZSVe experience on the application of the above-mentioned standards for the PTs, with focus on the Enterobacteriaceae enumeration one. Freeze-dried food matrices contaminated with American Type Culture Collection bacterial strains were used as test samples for each microbiological PT organised by IZSVe. The sample homogeneity and stability were verified prior to distribution to participants and throughout the PT, respectively. The participating laboratories analysed samples using their routine methods, and results were transmitted to IZSVe. Data and methods used by each participating laboratory were analysed in order to evaluate the laboratory performance. With reference to the Enterobacteriaceae PT, the test samples were homogeneous and stable. In addition, most laboratory results were obtained using equivalent test methods. Statistical approaches applied to analyse data generated from all participating laboratories revealed similar outcomes as no significant outlying count and only 5?% of unacceptable results were observed. Finally, the z-score, with the standard deviation that does not vary from round toround, was applied to compare and to evaluate the performance of each laboratory over time highlighting possible persistent trends over several rounds.     

Artifacts related to N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide derivatization of citrulline revealed by gas chromatography–mass spectrometry using both electron and chemical ionization

Derivatization with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) was used for gas chromatography–mass spectrometry (GC–MS) analysis of citrulline and ornithine. Aqueous 50 μl aliquots at 1 and 10 mM concentrations were dried and derivatized separately, and 70 eV electron ionization or CH₄ positive chemical ionization were used. Ornithine produced a single GC peak. Physiological citrulline concentrations produced GC artifact peaks for the ornithine derivative, and a compound consistent with elimination of a water molecule from the tri-tert-butyldimethylsilyl (TBDMS) citrulline derivative. A third GC peak obtained using 10 mM citrulline concentrations gave a mass spectrum consistent with a mixture of true tri- and tetra-TBDMS citrulline. Analyses of ¹³C-ureido-labeled citrulline confirmed the presence of the true TBDMS citrulline derivatives produced from 10 mM samples and provided evidence that the TBDMS ornithine artifact results from loss of TBDMS isocyanate from tetra-TBDMS citrulline. Linear-programmed temperature GC retention index data relative to n-alkanes are reported for observed GC peaks.     

Fluid-Structure-Interaction-Analysis concerning Damping Features of Viscous Fluids

This work deals with Fluid-Structure-Interaction (FSI) concerning damping characteristics of viscous liquids, which are investigated to make the offshore structures more secure and efficient. On that account, we modeled a damping element prototype consisting essentially of an elastic cover that is attached to the cylindrical mono pile foundation at the height of waves. Within the framework of FSI, the impact of breaking waves on a three-dimensional model of a damping element prototype corresponding to [1] is simulated. In order to measure the influence of different liquid properties on the damping of the impact, the calculations are set up using newtonian and non-newtonian fluids with varying viscosity. For the non-newtonian investigation verification is carried out with a CFD model. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A new method for asperphenamate synthesis and its antimicrobial activity evaluation

Asperphenamate is a natural phenylalanine derivative. This compound was produced through a new, two-step synthetic route. It was also evaluated by the antimicrobial activity of the pure substance against Escherichia coli, Staphylococcus aureus and Cladosporium herbarum.